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i have 3 kvm hosts running open vswitch with many virtual machines.

These vms are on two separate tenants and GRE tunnel carries private traffic between these 3 hosts.

But is there a better way to do GRE tunneling,because currently these GRE tunnels are on mesh and if i want to extend from 3 hosts to 10 hosts i should make 9 connections to each other.

Is it possible to implement star topology with open vswitch.

Kevin Parker
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1 Answers1

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That may not be a solution since that centralized open vswicth host can become traffic bottleneck.

but you can do that by specifying all other hosts to use central host as endpoint

from each hosts

ovs-vsctl add-port br1 gr1 -- set interface gr1 type=gre options:remote_ip=IP OF OVS CENTRAL SWITCH

and from central ovs specify each hosts ip

done

but the best way is to use open vswitch vlan tag to seperate traffic with in GRE.

ananthan
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  • i don't understand how that switch becomes bottleneck. – Kevin Parker Jun 03 '13 at 05:42
  • since ovs controller is on user space,for many different flows it can result in heavy cpu usage due to too many context switch and can result in packet loss. Check here http://goo.gl/QobpT – ananthan Jun 03 '13 at 05:44
  • For me the most horrifying part of the star solution is not the bottleneck, but the SPoF (single point of failure).. – neutrinus Apr 19 '14 at 12:53